// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import '../types/types.dart';

/// Interface for callbacks made by [WebViewPlatformController].
///
/// The webview plugin implements this class, and passes an instance to the [WebViewPlatformController].
/// [WebViewPlatformController] is notifying this handler on events that happened on the platform's webview.
abstract class WebViewPlatformCallbacksHandler {
  /// Invoked by [WebViewPlatformController] when a navigation request is pending.
  ///
  /// If true is returned the navigation is allowed, otherwise it is blocked.
  FutureOr<bool> onNavigationRequest(
      {required String url, required bool isForMainFrame});

  /// Invoked by [WebViewPlatformController] when a page has started loading.
  void onPageStarted(String url);

  /// Invoked by [WebViewPlatformController] when a page has finished loading.
  void onPageFinished(String url);

  /// Invoked by [WebViewPlatformController] when a page is loading.
  /// Only works when [WebSettings.hasProgressTracking] is set to `true`.
  void onProgress(int progress);

  /// Invoked by [WebViewPlatformController] when the webview's URL has changed.
  ///
  /// Unlike [onPageStarted], [onProgress], and [onPageFinished],
  /// [onUrlChanged] also fires when navigating without a full page load
  /// e.g. when navigating within a single page application.
  void onUrlChanged(String url);

  /// Report web resource loading error to the host application.
  void onWebResourceError(WebResourceError error);
}